Normally a container holder, such as a gas can holder is made specially for a certain size container. Whereas a smaller size container may fit into a container holder made for a larger size, it tends to be unstable. This creates a dangerous situation particularly in a moving vehicle such as a fire truck or a boat, in which the container must robustly fit into the container holder so that it will not fall out of the container holder or cause spill during the movement of the vehicle.
This document describes a system that addresses the issues described above and other issues too.